Bundle Branches — ECG/EKG Terminology

Definition: The left and right branches of the Bundle of His that conduct impulses down the interventricular septum to the ventricles.

Key Facts

• Right and left branches conduct impulses from His bundle to respective ventricles.
• Left bundle further divides into fascicles supporting coordinated LV activation.
• Branch block delays ventricular depolarization and widens QRS.

ECG Connection: Right or left bundle delay creates characteristic wide-QRS morphologies in precordial leads.

Why It Matters: New bundle branch block with symptoms can indicate acute ischemic or structural disease.